How to know in what environment the code runs?

Question

In the layout file of haml I would like to determine whether we are in our development and build environments. We're using Middleman.

I would like to do something like this:

- if environment == 'development'
    / Development Code
    = javascript_include_tag "Dev.js"

I tried to access Ruby's environment variable, as well as define a custom variable in the config.rb file with no success.

Answer 1

You’ve almost got it right – you need to check against a symbol rather than a string:

- if environment == :development
    / Development Code
    = javascript_include_tag "Dev.js"

Middleman also adds the development? and build? methods which may be easier to use:

- if development?
    / Development Code
    = javascript_include_tag "Dev.js"

This works with ERB too:

<% if development? %>
<!-- Development Code -->
<%= javascript_include_tag "Dev.js" %>
<% end %>